Hopefully this is the right place to create this thread, if it should be posted anywhere at all.
It is intended to share my opinions based on experience regarding composing for projects.
Hopefully project organizers and musicians engaging in projects alike, will benefit from this.
Since this is a thread, please share your opinions, and discuss this topic so everyone including me will learn more.
Tell musicians what to do, not how to do it.
Many directors are passionate about their projects, and that's a good thing.
It's important to know what you want, in order to express yourself and make it work. But don't let this turn you into a control freak.
If other team members too feel it's their own thing, and be proud of their work,
they will provide the best work. Don't take away their enthusiasm and creativity by forcing limitations on them.
Instead acknowledge other people's skills. If you don't value a musicians skills, you've adopted the wrong one. Choose a composer who's style you think suits your project, and trust they will be able to do that.
What this means in practice; avoid technical details. Especially if you don't know what you're talking about.
What you should do do instead is say where music is wanted, and explain what a scene/level/whatever is about, so the composer can deside how to achieve this goal.
Examples
Wrong way to do it: level 5 - This is the second ice level, so same as previous level, but with more vibe. Minor crashes this time but a major crunch, a tiny bit of dub in between the syncopes, a repetive piano beat with lots of variation played by a saxophone sounding synth, an upfront reagea groove on the 1rst 2nd and 5d count (skip the 7th), , lesbian intercourse, an electro-acoustic drum riff that drags the song on, but should not be consiously determinable (when people think "Hey that's an electro-acoustic drum riff that drags the song on.", than you've failed), and some close by techno in the background. Retro neo-classical, but still modern sounding (: not what in the 50s they thought was futuristic, but what the day after tomorrow they observe as yesterday (you know what I mean ;))).
Right way: level 5 - After the snow storm of level 4, the hero enters the shelter of an ice cavern. It's composed of beautiful ice crystals, but the ground is slippery and there are dangerous pits. I want you to capture the beauty of the ice cavern, as well as the dangers of it. I like you to set this song appart from the previous in some way, even though they're both ice levels. There won't be a map sequence or victory fanfare in between, but this song imediately follows up the one of level 4.
A lot of directors nowadays sent youtube links to songs they think the composer's work should sound like. This is a double edged sword. It may be clearer than a discription (alone). Still it's very limiting to the composer's creativity which is what you should avoid. The composer will provide better work when he/she does what he/she's good at, than when he/she tries to immitate someone else. The new work always has to be different than the example in one way or the other (otherwise it's a one on one copy). It's not always clear what exactly the director likes about the example.
Once a game creator sent me an example of a rap song with electronic beat, and said "I want this, but without the rap and electronic instruments, and no hip hop, but classical instead so it fits in a medieval rpg setting." Can you imagine I didn't know what to do with that?
The composer has to be in the loop.
The more a composer knows about the project, the better the work will fit the project. As a director this means you should show the composer as much as you can about the project. eg screenplay, storyboard, concept art, unfinished cuts, demos, etc.
The composer has to be open to this, and not just stay in his/her own little world. The composer has to try to actively understand the project. Show interest, ask the right questions etc.
Communicate.
This is as important for the musician as it is for the director, since communication has to come from both directions. Be approachable. There are several mediums to communicate so be skilled in as many as you can, and try to find one that works for both. Keep checking in on each other every on or two weeks. If one sends an e-mail, better answer as quick as you can. I know people are busy, but it's simply better when you don't leave coworkers hanging.
I know it seems like an open door, but here is where it goes wrong most of the time. Sending out an e-mail each week with new songs and questions, only to get a response several months later saying "Awesome", is very frustrating a demotivating (and yes this literally happened).
Make clear agreements.
Some people like to make strict schedules, others need freedom and prefer to just see what happens. This often clashes. Any way, in order to make things happen you have to make certain agreements. Make it clear what one expects of the other. If things don't work out, let it know as soon as possible, so new arrangements can be made.
Avoid shifting finish lines. Few things are more frustrating than thinking you're (almost) done, only to get more work, and more after that, and after that. What you than get is people stop doing anything because they know that when they're done they only get more work. People have to have a sense of when their work is finished. Ask for a reasonable amount of work, and allow the composer to plan it.
I once was asked to make an already lengthy soundtrack, and when after four months I was 80% done I got news plans were changed. The amount of work I had to do was trippled, and half of what I'd done wouldn't be used. Not nice.
The people involved have an obligation to meet their agreements. Once a project leader told me he didn't have to finish the project. This is very honest, but I had to tell him I wouldn't waste any of my time on it then. Worse would have been if I wasted several years of my life on a project, only to have the project canceled. The only thing you can do about that is take on assignments you think will see the light. Have a back-up plan, like "If the project won't be finished I can use this sound track as an album of my own, or for another project."
Now I notice I focus a little too much on the negative side, and I apologize for that. I don't mean to criticize directors. I respect people organising a project, and I love to be on board of some interesting ones. Just providing my point of view. The problems you encounter stay with you more than the things that go smoothly.
Any directors, musicians an other people who read this, please comment on what your collaboration experiences and opinions are, and whether or not you agree with what I said. Fire away.